Some buggy NPTL threading implementations include the guard area within
the stack size allocations. In this case we need to allocate an extra
page to account for the guard area since we only have two pages of usable
stack on Linux. Added an autoconf test that detects such implementations
by running a test program designed to segfault if the bug is present.
Set a flag NPTL_GUARD_WITHIN_STACK that is tested to decide if extra
stack space must be allocated for the guard area.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
It turns out the gcc option -Wframe-larger-than=<size> which I recently
added to the build system is not supported in older versions of gcc.
Since this is just a flag to ensure I keep stack usage under control
I've added a configure check to detect if gcc supports it. If it's
available we use it in the proper places, if it's not we don't.
This include updating all the Makefile.am to have the correct
include paths and libraries. In addition, the zlib m4 macro was
updated to more correctly integrate with the Makefiles. And I
added two new macros libblkid and libuuid which will be needed by
subsequent commits for blkid and uuid support respectively. The
blkid support is optional, the uuid support is mandatory for libefi.
Ned Bass
Brian Behlendorf